exhaust question...not a noob HP question
 

I have a 2007 2.3 N/A Mazda3. I am looking to get a little bit more sound out of the stock exhaust. It's my wife's car so she's not worried about HP. I dont really feel like spending $400+ on a aftermarket exhaust system.
I was looking underneath the car and I'm wondering if the big boxy looking piece in the middle of the car is the muffler. It looks like a muffler to me but it could be a resonator.
What has been done to add more sound...not obnoxious, but deeper, and a tad bit louder. I have a Dynamax high-flow cat laying around would that help?


Thanks for your time.


Brian

That's the stock catalytic converter. If your Dynamax is made for a Mazda3 and bolts right up (flanges, bung for smog equipment, etc), it'll make a nice difference in sound and you'll probably even pick up a few HP. If it doesn't it might be easier to pick up a Magnaflow or Bonez cat that fits.

You might get a CEL(check engine light) if you run a hi flow cat, though.